Michigan’s campaign managers and consultants, pollsters, advisers and advertising gurus may want to close this post and avoid reading the harsh message it offers.

A carefully crafted study conducted by two California political scientists concludes that, essentially, political campaigning has no effect on election outcomes. Specifically, the researchers found that outreach activity by campaigns, including door to door canvassing, phone banking, robocalls, and even direct-mail advertising has basically no effect on voters’ choice of candidate in general elections.

The standard campaign activities embraced over many decades sometimes still work, especially in primaries, special elections and on ballot proposals. But in regularly scheduled November general elections, it’s mostly effective at turning out a candidate’s base.

The bottom line is that blind partisanship among the electorate has become so intense that campaign efforts affect only about one out of 800 voters in a general.

The academic study included 49 experiments conducted in the field, typically with cooperation and full access from the campaigns that were being observed. It involved comparing the political views and votes cast by voters who were targeted by a spirited offensive versus those who received little attention.

The new study’s authors, University of California-Berkeley’s Joshua Kalla and Stanford’s David Broockman, conclude that undecided voters and those identified as voters who can be flipped were not persuaded by any of the traditional game plans.

Kalla and Broockman suggest that the substantial campaign donors who loom large over each election season should consider directing their cash to primary elections and ballot initiatives.

Most political pros years ago concluded that campaign billboards and lawn signs are a waste of money as their only value is in improving the name ID of a newcomer candidate

But the study found that most of the typical campaign tactics offer little bang for the buck.

“Campaigns probably need to get more creative and think more outside the box,” Broockman said in a media interview. “Whatever box they are working within now doesn’t usually produce results.”

The methodology used in these field experiments is rather complicated but apparently the conclusions were the same whether the researchers studied the impact on campaigns for congressional seats, statewide races or local offices.

In addition, the Vox news site reports that the timing of campaign offensives has an effect that was “indistinguishable from zero:”

Kalla and Broockman found that, if the campaign action (canvass, phone call, etc.) happens within two months of Election Day, the average effect on voter preferences was effectively zero. About one in 800 people reached were persuaded, they estimate.

By contrast, when the campaign action happens well before Election Day, and the effects are measured quickly thereafter, there’s a real impact on opinions — but it disappears before Election Day. The sooner you get to the election, the more voters get set in their ways and choose candidates by their partisan alignment, and aren’t persuadable by additional campaigning.

Partisanship seems to be the major factor here… While your partisan identity tells you how to vote in general elections, it’s of much less help for ballot initiatives and primary elections. (By definition, the rivals in a primary election come from the same party — so cues from party leadership tend to be subtler.)

“Although campaigns may have some scope for persuasion in competitive primary elections, where there is no partisan cue, in general elections there are few considerations they can provide today’s voters that would lead them to abandon their party,” Kalla and Broockman write.

According to The Atlantic, Broockman and Kalla also estimated that the effect of television and online ads is zero, although only a small portion of their data speaks directly to that point.

The Atlantic sees the study as all-encompassing in its delivery of a body blow to the multi-billion dollar electioneering industry:

For every flyer stuck in a mailbox, every door knocked by an earnest volunteer, and every candidate message left on an answering machine, there was no measurable change in voting outcomes.

Broockman said … “Just because there are certain beliefs that many people hold about what works in campaigns doesn’t mean those things are likely to be true. Humans are very good at fooling themselves, especially when there are consulting fees involved. We need to move to a higher standard of evidence. If I were a campaign candidate or donor … that’s what I would demand.”